A former New Zealand politician says the government must repeal an immigration law discriminating Samoans because it is in breach of international human rights obligations.

Anae Arthur Anae says the Citizenship Western Samoan Act of 1982 exposes New Zealand for its racist bias towards Samoans who are entitled to dual citizenship.

Anae addressed thousands of Samoans at New Zealand's parliament to hand over a petition with 100-thousand signatures demanding that the act be repealed.

The Act says Samoans born before 1948 don't qualify for New Zealand citizenship.

It was introduced to counter a Privy Council ruling that Samoans born between 1924 and 1949 were automatically New Zealand citizens.

Anae, who organised the petition, says the act testifies to New Zealand's human rights offences against Samoans and should be repealed.

"New Zealand has an international reputation about human rights issues in other countries and yet has kept quiet about its own internal issues which contradict the international human rights covenants, namely the dawn raids by police with dogs during the 70's and the passing of and the passing of the Citizenship Western Samoan Act of 1982. The Samoans want this injustice to be sorted out within New Zealand."

Meanwhile in Samoa, part of Apia's main road was closed to traffic for marchers to deliver the petition to the New Zealand high commission.

In an address, the march leader, Leota Itu Au Ale, asked the New Zealand government to repeal the citizenship act.

The secretary general of the Mau Citizenship New Zealand for Samoa, Maiava Peteru, handed the petition to the high commissioner, Penelope Ridings.

She said she would pass the petition to the government for its consideration.

The high commissioner said the petition would follow the normal parliamentary process and be referred to the Clerk of the House.

She said the Clerk would then decide on which parliamentary select committee the petition would be sent to.